Identification of a discrete subpopulation of spinal cord ependymal cells with neural stem cell properties.

Spinal cord ependymal cells display neural stem cell properties in vitro and generate scar-forming astrocytes and remyelinating oligodendrocytes after injury. We report that ependymal cells are functionally heterogeneous and identify a small subpopulation (8% of ependymal cells and 0.1% of all cells in a spinal cord segment), which we denote ependymal A (EpA) cells, that accounts for the in vitro stem cell potential in the adult spinal cord.

Divergent clonal differentiation trajectories establish CD8 memory T cell heterogeneity during acute viral infections in humans.

The CD8 T cell response to an antigen is composed of many T cell clones with unique T cell receptors, together forming a heterogeneous repertoire of effector and memory cells. How individual T cell clones contribute to this heterogeneity throughout immune responses remains largely unknown. In this study, we longitudinally track human CD8 T cell clones expanding in response to yellow fever virus (YFV) vaccination at the single-cell level.

A latent lineage potential in resident neural stem cells enables spinal cord repair.

Injuries to the central nervous system (CNS) are inefficiently repaired. Resident neural stem cells manifest a limited contribution to cell replacement. We have uncovered a latent potential in neural stem cells to replace large numbers of lost oligodendrocytes in the injured mouse spinal cord.

Role of endogenous neural stem cells in spinal cord injury and repair.

Spinal cord injury is followed by glial scar formation, which has positive and negative effects on recovery from the lesion. More than half of the astrocytes in the glial scar are generated by ependymal cells, the neural stem cells in the spinal cord. We recently demonstrated that the neural stem cell-derived scar component has several beneficial functions, including restricting tissue damage and neural loss after spinal cord injury.

Resident neural stem cells restrict tissue damage and neuronal loss after spinal cord injury in mice.

Central nervous system injuries are accompanied by scar formation. It has been difficult to delineate the precise role of the scar, as it is made by several different cell types, which may limit the damage but also inhibit axonal regrowth. We show that scarring by neural stem cell-derived astrocytes is required to restrict secondary enlargement of the lesion and further axonal loss after spinal cord injury.

Neural stem cells in the adult spinal cord.

Spinal cord injury results in cell loss, disruption of neural circuitry and chronic functional impairment. Several different cell types generate progeny in response to injury, which participate in scar formation and remyelination. Work over the last few years has identified neural stem cells and delineated the stem cell potential of different cell populations in the adult spinal cord under homeostasis and in response to injury.